US6735984B1 - Making an optical fiber preform including reducing the length of a deposition layer - Google Patents

Making an optical fiber preform including reducing the length of a deposition layer Download PDF

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Publication number
US6735984B1
US6735984B1 US09/532,968 US53296800A US6735984B1 US 6735984 B1 US6735984 B1 US 6735984B1 US 53296800 A US53296800 A US 53296800A US 6735984 B1 US6735984 B1 US 6735984B1
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United States
Prior art keywords
preform
reduction
length
layer
deposited
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Expired - Fee Related, expires
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US09/532,968
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English (en)
Inventor
Jacques Jolly
Rémi Fauche
Jean-Florent Campion
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Alcatel Lucent SAS
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Alcatel SA
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    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/012—Manufacture of preforms for drawing fibres or filaments
    • C03B37/0128—Manufacture of preforms for drawing fibres or filaments starting from pulverulent glass
    • C03B37/01291—Manufacture of preforms for drawing fibres or filaments starting from pulverulent glass by progressive melting, e.g. melting glass powder during delivery to and adhering the so-formed melt to a target or preform, e.g. the Plasma Oxidation Deposition [POD] process
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/012—Manufacture of preforms for drawing fibres or filaments
    • C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
    • C03B37/01413—Reactant delivery systems
    • C03B37/0142—Reactant deposition burners
    • C03B37/01426—Plasma deposition burners or torches
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/012—Manufacture of preforms for drawing fibres or filaments
    • C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
    • C03B37/01446—Thermal after-treatment of preforms, e.g. dehydrating, consolidating, sintering
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/012—Manufacture of preforms for drawing fibres or filaments
    • C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
    • C03B37/01466—Means for changing or stabilising the diameter or form of tubes or rods
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2207/00—Glass deposition burners
    • C03B2207/60—Relationship between burner and deposit, e.g. position
    • C03B2207/66—Relative motion
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2207/00—Glass deposition burners
    • C03B2207/70—Control measures

Definitions

  • the invention relates to a method of manufacturing optical fiber preforms, which method is more particularly intended for manufacturing preforms of large diameter.
  • a known method of manufacturing or building up, i.e. “overcladding”, preforms designed for the production of optical fibers makes provision to deposit silica on a primary preform which is equipped with supporting end-pieces at its ends, and which is carried by means enabling it to move along its axis and to rotate relative to a flame of an inductive plasma torch, into which silica grains are injected and in which they are melted. That method makes it possible to manufacture a preform of determined thickness, starting from a primary preform that is thinner, by superposing a succession of concentrically-deposited layers of silica.
  • the respective lengths of the successive layers decrease so that the thickness of deposited silica that covers the preform and its end-pieces tapers uniformly towards the ends, from a central segment of determined length and diameter.
  • a conical shape is imparted to one of the ends of each preform so as to facilitate the subsequent fiber-drawing operations starting from said end.
  • the desired conical shape at the fiber-drawing end of the preform can be obtained by drawing the-end-pieces of the preform as overclad with silica in opposite directions, after the preform has been locally melted by being heated to the core, in a zone of the central segment that is situated in the vicinity of the end to be made conical.
  • Such drawing makes it possible to separate the preform from one of its two supporting end-pieces.
  • the intense heating performed for drawing purposes suffers from the drawback of giving rise to high silica evaporation, the evaporated silica then cooling and forming soot which falls back in particular on the preform. Such soot affects the transparency of the preform and increases its roughness.
  • a first drawing step causes the diameter of the preform in the zone that is heated for cleaving purposes to be reduced to a chosen diameter that is usually close to the diameter of a supporting end-piece.
  • a glazing operation is provided for removing the unwanted deposit that has formed on the cold portions of the preform that have received soot during the heating performed for the first drawing step. The glazing is performed by passing the preform through the flame of the plasma torch without any material being supplied.
  • a second drawing step terminates the separation in the smaller-diameter zone that is heated to the core for that purpose. The quantities of silica evaporated and re-deposited are small because of the small dimensions of the zone that is then heated.
  • That method including two separation steps is quite suitable when the preforms to be cleaved are of diameter that is not too large, e.g. of maximum diameter of about 80 mm.
  • the invention provides a method of manufacturing or building up, i.e. “overcladding”, an optical fiber preform in an installation provided with means enabling a preform held horizontally at its ends between two mounting points by supporting end-pieces to be rotated axially and to be moved relatively in translation.
  • preform are associated with material supply means, so as to enable the preform to be manufactured in successive passes corresponding to the preform and the torch being displaced relative to each other, with or without material being supplied, these displacements therefore leading either to a new layer of material being deposited on the preform, or to the most recent layer deposited being glazed.
  • the method makes provision to interpose a one-ended reduction in the length of at least one layer, during a pass and starting from one of the intermediate layers, while a succession of concentric layers of material are being deposited on the preform in a manner such that the respective lengths of the layers, which lengths are determined by the preform/torch relative displacements, are progressively shortened as a result of a progressive reduction in the lengths of the displacements, so that the thickness of deposited material that covers the preform and a portion of each of the end-pieces decreases uniformly towards the ends, said one-ended reduction in layer length leading to a limitation of the thickness of material deposited on one of the end-pieces and on a limited-length preform zone that is longitudinally adjacent to said end-piece, at the level set by the layer deposited immediately prior to said one-ended reduction.
  • the method includes at least one hot drawing operation performed to separate a preform from one of the end-pieces in said limited-length preform zone which is adjacent to said end-piece, after said succession of layers required for forming the preform has been deposited.
  • the method includes a hot-drawing operation performed in two steps, separated by a preform glazing operation, in said limited-length preform zone which is adjacent to an end-piece so as to separate the preform and said end-piece, the first drawing step being associated with heating to the core causing softening by melting in said limited-length preform zone, and producing a reduction in diameter, the second step also being associated with heating to the core causing softening by melting and achieving full separation.
  • FIG. 1 is a diagrammatic view of a known installation making it possible to implement the method of the invention for producing a preform
  • FIG. 2 is a diagrammatic view of a preform made using the method of the invention.
  • FIG. 3 is a diagrammatic view of a preform of the invention as obtained after separation.
  • the installation shown diagrammatically in FIG. 1 is assumed to make it possible to manufacture or to build up or “overclad” optical fiber preforms.
  • the installation makes it possible to obtain an overclad preform 1 starting from a primary preform 2 , of axis 4 , such an overclad preform being known from the prior art and shown diagrammatically in FIG. 2 .
  • the installation includes means 3 of the lathe type making it possible to rotate the preform axially as it is held horizontally at its ends via end-pieces 6 a , 6 b between two mounting points 3 a , 3 b .
  • the end-pieces are previously fixed to the ends of the primary preform.
  • One of them, referenced 6 a in this example remains secured to the finally-obtained preform, while the other, referenced 6 b in this example, is separated from the final preform so that an optical fiber can be obtained by performing a fiber-drawing operation known to the person skilled in the art.
  • the installation also includes plasma torch heater means 5 which are more generally positioned radially relative to the preform when said preform is held horizontally between the mounting points 3 a , 3 b .
  • Material supply means (not shown) are associated with the plasma torch. They are conventionally used to inject grains of silica into the flame of the torch which melts said grains.
  • the torch is positioned in known manner such that silica is deposited in localized manner on the preform. By moving the preform and the torch relative to each other, it is possible to deposit silica on a zone of limited width over the length of the preform, and by rotating the preform, it is possible to cover the entire preform with a deposit. It is possible for the torch to be displaced in translation relative to the preform, but the torch is more conventionally mounted on a lathe, and said lathe causes the preform as held by its ends to move in translation relative to the torch which is then fixed.
  • Overcladding a primary preform, such as 2 ′ in FIG. 2, so as to obtain a preform 1 or 1 ′ that can be used to produce a fiber, is performed by implementing successive passes to deposit a succession of superposed concentric layers. It is known that the lengths of the successive layers can be reduced progressively by progressively reducing the lengths of the preform/torch relative displacements parallel to the axis 4 of the preform. It is thus possible to make the thickness of deposited material that covers the primary preform and a portion of each of its end-pieces decrease progressively at the two ends and on either side of a central segment of uniform diameter, as shown in FIG. 1 .
  • Document EP-A-0 831 070 makes provision to perform the separation in two steps, between which a glazing stage is interposed.
  • the glazing stage aims to remove the silica that has been re-deposited during the first of the separation steps.
  • the diameter of the preform 1 is annularly reduced to a value which corresponds, for example, to the diameter of an end-piece, in a determined zone 10 in which the separation is to take place. As shown in FIG.
  • this zone 10 is chosen to be in the vicinity of the end-piece 6 b to be removed, and following on from the portion 9 of the preform that is constituted by the successive deposition of layers of silica on the primary preform and on the end-piece 6 b , where they are joined together prior to separation.
  • the evaporation and the corresponding re-deposition are thus significantly smaller than those produced during the preceding step, insofar as the softening to be performed affects only the zone 10 and therefore concerns only a relatively small quantity of silica.
  • each concentric layer is a function of the length of relative displacement provided between the preform and the torch 5 in operation along the longitudinal axis 4 of said preform, for the purpose of depositing said layer.
  • a preform 1 ′ obtained by implementing the method of the invention is made from a commonly-used primary preform 2 ′, of circularly cylindrical appearance, carried at its ends by end-pieces 6 a ′ and 6 b ′, as shown in FIG. 2 .
  • the concentric layers are progressively shortened at either end of a central segment, as defined by a variation relationship that is, for example, linear and that is imposed by the preform/torch relative displacements.
  • the ends of the preform being overclad tend to constitute points, with each end, taking up an approximately conical appearance.
  • a one-ended reduction in layer length is imposed by a corresponding reduction in the relative displacement between the torch and the preform.
  • This one-ended reduction is performed during an overcladding pass during which the preform 1 ′ being overclad is overclad with a layer of material.
  • the reduction is, for example, set to a value L 1 lying in the range 10 millimeters to 200 millimeters.
  • it may be triggered when a determined diameter value D 1 is reached for the preform being overclad, as a result of the successive depositions of material during the passes, which passes have led to a predetermined number of layers being formed.
  • the diameter value D 1 is chosen to be greater than the diameter of the end-piece 6 b ′, and preferably less than 70 millimeters.
  • the deposition of the concentric layers is then continued on the preform la starting from the layer whose length has been reduced at one end, the deposition being continued with a relationship of decreasing variation in length which is optionally the same decreasing relationship as used previously for the layers which, by being superposed, made it possible to reach the thickness of material corresponding to the diameter D 1 .
  • This decreasing relationship is, for example, a linear relationship leading to a circularly-symmetrical intermediate segment being obtained between the cylindrical central portion of the overclad preform 1 ′ and the cylindrical segment 10 ′ of diameter D 1 which results from the one-ended reduction in length performed at the end at which the end-piece 6 b ′ is situated.
  • said decreasing relationship results in a series of setpoints whose characteristics are supplied to a programmable logic controller (not shown) which is assigned to controlling the preform/torch displacements.
  • the decreasing relationship is assumed to be the same for both ends of the preform in the example shown in FIG. 2 .
  • a different decreasing relationship may also be considered, firstly for each preform end, and secondly for the intermediate portion connecting the cylindrical central segment of the preform to the cylindrical segment 10 ′.
  • the purpose of this is to obtain one preform end whose shape, after removal of the end-piece 6 b ′, differs from that of a cone, e.g. by being substantially bulb-shaped.
  • the variation relationship is chosen to obtain an unbroken curved connection between a circularly-symmetrical intermediate segment and the cylindrical central segment of the preform.
  • a non-linear decrease makes it possible, for example, to obtain a pointed end, united with the central segment by a curved junction whose appearance is that of a paraboloid of revolution which curves without any discontinuity in the zone where it joins the central segment.
  • the separation is effected in that limited-length zone of the preform which is adjacent to the end-piece and which makes up the cylindrical segment 10 ′ with it.
  • the interface zone where an end-piece is united with a preform, is not used for fiber-drawing because it is not sufficiently homogeneous as a result of the glass-glass weld by means of which the end-piece and the preform are secured together.
  • the separation is effected by drawing the glass constituting the segment 10 ′ which is made locally soft by being heated to the core by means of the plasma torch 5 , in the zone of the preform that includes the segment 10 ′ and that is adjacent to the end-piece. This drawing is performed by exerting axial traction in opposite directions via the end-pieces 6 a ′ and 6 b ′. It results in the link that existed between the preform 1 ′ and its end-piece 6 b ′ being cleaved, as shown diagrammatically in FIG. 3 .
  • This cleaving is facilitated by the intensive heating being localized, as created by the heating to the core for the purpose of softening the glass by melting it, in a portion of the segment 10 ′ and by the fact that the segment is of small diameter relative to the central segment of the preform 1 ′.
  • a substantially conical shape is obtained at that end of the preform which has been broken away from the end-piece 6 b ′ and from the residual portion of preform 9 ′ that the end-piece continues to support after separation.
  • the choice of the shape of the end of the preform that is best suited to fiber-drawing is obtained by acting on the factors involved in the separation stage performed by drawing, and in particular on the length variation relationship chosen for the superposed concentric layers of the junction between the central cylindrical segment of the overclad preform 1 ′ and the segment 10 ′.
  • the duration of the separation operation is reduced because the diameter of the segment 10 ′ is itself limited compared with the overall outside diameter of the preform. This also limits the unwanted quantity of silica re-deposited during the heating to the core.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Thermal Sciences (AREA)
  • Manufacture, Treatment Of Glass Fibers (AREA)
  • Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
US09/532,968 1999-04-01 2000-03-22 Making an optical fiber preform including reducing the length of a deposition layer Expired - Fee Related US6735984B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9904074A FR2791663B1 (fr) 1999-04-01 1999-04-01 Procede de fabrication d'une reforme pour fibre optique et plus particulierement d'une preforme de fort diametre
FR9904074 1999-04-01

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US (1) US6735984B1 (fr)
EP (1) EP1041048B1 (fr)
JP (1) JP2000290034A (fr)
AT (1) ATE223877T1 (fr)
DE (1) DE60000424T2 (fr)
ES (1) ES2182758T3 (fr)
FR (1) FR2791663B1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040206127A1 (en) * 2003-03-31 2004-10-21 Coffey Calvin T. Method and apparatus for making soot
WO2006106068A3 (fr) * 2005-04-05 2006-12-14 Heraeus Tenevo Gmbh Procede pour la fabrication d'une preforme pour fibres optiques
US20100024486A1 (en) * 2008-08-04 2010-02-04 Fujikura Ltd. Method of producing optical fiber preform

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116062983B (zh) * 2023-02-17 2024-08-20 长飞光纤光缆股份有限公司 一种具有稳定气流场的沉积腔

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5211732A (en) * 1990-09-20 1993-05-18 Corning Incorporated Method for forming a porous glass preform
EP0727392A1 (fr) 1995-02-14 1996-08-21 Alcatel Fibres Optiques Procédé de traitement de surface d'une préforme, procédé de réalisation d'une préforme comprenant un tel procédé de traitement de surface, préforme réalisée par la mise en oeuvre de tels procédés
EP0831070A1 (fr) 1996-09-24 1998-03-25 Alcatel Fibres Optiques Procédé de fabrication d'une préforme pour fibre optique
US5925163A (en) * 1993-12-27 1999-07-20 Corning, Inc. Method of making an optical fiber with an axially decreasing group velocity dispersion

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01212246A (ja) * 1988-02-17 1989-08-25 Fujikura Ltd 光ファイバ母材の製造方法
JPH0383831A (ja) * 1989-08-25 1991-04-09 Fujikura Ltd 光ファイバ母材の製造方法
JP2612941B2 (ja) * 1989-09-22 1997-05-21 信越化学工業株式会社 光ファイバ多孔質母材の製造方法
JPH05221660A (ja) * 1992-02-14 1993-08-31 Furukawa Electric Co Ltd:The ガラス微粒子堆積方法
JPH06239640A (ja) * 1993-02-17 1994-08-30 Fujikura Ltd 光ファイバ母材の製造方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5211732A (en) * 1990-09-20 1993-05-18 Corning Incorporated Method for forming a porous glass preform
US5925163A (en) * 1993-12-27 1999-07-20 Corning, Inc. Method of making an optical fiber with an axially decreasing group velocity dispersion
EP0727392A1 (fr) 1995-02-14 1996-08-21 Alcatel Fibres Optiques Procédé de traitement de surface d'une préforme, procédé de réalisation d'une préforme comprenant un tel procédé de traitement de surface, préforme réalisée par la mise en oeuvre de tels procédés
EP0831070A1 (fr) 1996-09-24 1998-03-25 Alcatel Fibres Optiques Procédé de fabrication d'une préforme pour fibre optique
US5979189A (en) * 1996-09-24 1999-11-09 Alcatel Fibres Optiques Method of separating and glazing an optical fiber preform

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040206127A1 (en) * 2003-03-31 2004-10-21 Coffey Calvin T. Method and apparatus for making soot
WO2006106068A3 (fr) * 2005-04-05 2006-12-14 Heraeus Tenevo Gmbh Procede pour la fabrication d'une preforme pour fibres optiques
US20100024486A1 (en) * 2008-08-04 2010-02-04 Fujikura Ltd. Method of producing optical fiber preform

Also Published As

Publication number Publication date
ES2182758T3 (es) 2003-03-16
ATE223877T1 (de) 2002-09-15
EP1041048B1 (fr) 2002-09-11
EP1041048A1 (fr) 2000-10-04
DE60000424T2 (de) 2003-05-15
FR2791663A1 (fr) 2000-10-06
JP2000290034A (ja) 2000-10-17
DE60000424D1 (de) 2002-10-17
FR2791663B1 (fr) 2001-06-29

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